The curriculum of Trinity Lutheran School meets the accreditation requirements of the State of Illinois and the guidelines for Lutheran schools. Trinity is accredited by the National Lutheran Schools Accreditation (NLSA), and also by AdvancED (Accreditation Commission).

Trinity is one of the few schools to hold a double accreditation:

NLSA: Serves as the accrediting body for Lutheran Church-Missouri Synod schools across the United States and the world. NLSA encourages, assists, and recognizes schools that provide quality Christian education and engage in continuous improvement.

AdvancED: Is the largest community of education professionals in the world. They conduct rigorous, on-site reviews of a variety of educational institutions and systems to ensure that all learners realize their full potential. The goal of AdvancED is not to certify that educational institutions are good enough, rather, to help these institutions continuously improve.